The present invention relates to a hydraulic braking device, and also to a clutch particularly useful in such braking device. The invention is especially applicable to human powered vehicles (e.g. bicycles, tricycles) used for transportation or sport, such as described in the above-cited copending patent applications. The invention is therefore described below with respect to such a vehicle, but it will be appreciated that various features of the invention could advantageously be used in many other applications.
Vehicles conventionally include mechanical braking devices, such as friction disc brakes, for braking the vehicle. In fuel powered vehicles, a considerable part of the braking is effected by the vehicle engine, thereby subjecting the mechanical brakes to less wear and tear, particularly during long descents. Since human powered vehicles do not include an engine, they rely on the conventional friction brakes for braking the vehicle; this subjects the friction brakes to considerable wear and tear particularly during long vehicle descents.
An object of the present invention is to provide a hydraulic braking system for braking a driven device, which hydraulic braking system is particularly, but not exclusively, useful in human powered vehicles. Another object of the invention is to provide a clutch construction particularly, but not exclusively, useful in the hydraulic braking system of the present invention. A further object is to provide a human powered vehicle including a hydraulic braking device; and a still further object is to provide a releasable retainer device particularly useful in the clutch of the hydraulic braking device for stably retaining the two jaws of the clutch in their engaged and disengaged positions.